The eXtensible Markup Language (XML) is a World Wide Web Consortium (W3C) endorsed standard for document and data representation that provides a generic syntax to mark up data with human-readable tags. XML does not have a fixed set of tags and thus allows users to define such tags as long as they conform to the XML standard. Data may be stored in XML documents as strings of text that are surrounded by text markup. The W3C has codified XML's abstract data model in a specification called the XML information set (XML Infoset). XML Schemas also may be used to apply a structure to the XML format and content. In the case of an XML Schema, a diagram, plan, or framework for XML data in a document may be defined. Although XML is a well-known format that may easily describe the contents of a document, other non-XML formatted data may be desirable in the same database. This produces a potential querying problem because of the inherent incompatibility. An example of such an incompatibility is the presence XML content in a relational database.
Search engines on relational databases are well-known. A typical standard is the Structured Query Language (SQL) relational database language. Both XML coded and SQL data may be placed in a single database to indicate some data relationship. However, the search of that database may become difficult because the XML values stored in the rows of the SQL database may appear as large objects expressed in text or binary form. Although the SQL relational database information may be fast and efficient, searching the large objects in the XML coded information of the relational database may be inefficient. Typically, the inefficiency results from the excessive time and computer resource consumption involved in opening and examining of the XML coded large objects every time a query is made on the XML data in the SQL database.
Thus, there is a need for a method and system which can efficiently perform a search on XML encoded data in either a stand-alone XML document or in combination with relational data such as that stored in a SQL table. The present invention addresses the aforementioned needs and solves them with additional advantages as expressed herein.